hostap/src/eap_peer/mschapv2.c

124 lines
3.7 KiB
C
Raw Normal View History

/*
* MSCHAPV2 (RFC 2759)
* Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*/
#include "includes.h"
#include "common.h"
#include "ms_funcs.h"
#include "mschapv2.h"
const u8 * mschapv2_remove_domain(const u8 *username, size_t *len)
{
size_t i;
/*
* MSCHAPv2 does not include optional domain name in the
* challenge-response calculation, so remove domain prefix
* (if present).
*/
for (i = 0; i < *len; i++) {
if (username[i] == '\\') {
*len -= i + 1;
return username + i + 1;
}
}
return username;
}
int mschapv2_derive_response(const u8 *identity, size_t identity_len,
const u8 *password, size_t password_len,
int pwhash,
const u8 *auth_challenge,
const u8 *peer_challenge,
u8 *nt_response, u8 *auth_response,
u8 *master_key)
{
const u8 *username;
size_t username_len;
u8 password_hash[16], password_hash_hash[16];
wpa_hexdump_ascii(MSG_DEBUG, "MSCHAPV2: Identity",
identity, identity_len);
username_len = identity_len;
username = mschapv2_remove_domain(identity, &username_len);
wpa_hexdump_ascii(MSG_DEBUG, "MSCHAPV2: Username",
username, username_len);
wpa_hexdump(MSG_DEBUG, "MSCHAPV2: auth_challenge",
auth_challenge, MSCHAPV2_CHAL_LEN);
wpa_hexdump(MSG_DEBUG, "MSCHAPV2: peer_challenge",
peer_challenge, MSCHAPV2_CHAL_LEN);
wpa_hexdump_ascii(MSG_DEBUG, "MSCHAPV2: username",
username, username_len);
/* Authenticator response is not really needed yet, but calculate it
* here so that challenges need not be saved. */
if (pwhash) {
wpa_hexdump_key(MSG_DEBUG, "MSCHAPV2: password hash",
password, password_len);
generate_nt_response_pwhash(auth_challenge, peer_challenge,
username, username_len,
password, nt_response);
generate_authenticator_response_pwhash(
password, peer_challenge, auth_challenge,
username, username_len, nt_response, auth_response);
} else {
wpa_hexdump_ascii_key(MSG_DEBUG, "MSCHAPV2: password",
password, password_len);
generate_nt_response(auth_challenge, peer_challenge,
username, username_len,
password, password_len, nt_response);
generate_authenticator_response(password, password_len,
peer_challenge, auth_challenge,
username, username_len,
nt_response, auth_response);
}
wpa_hexdump(MSG_DEBUG, "MSCHAPV2: NT Response",
nt_response, MSCHAPV2_NT_RESPONSE_LEN);
wpa_hexdump(MSG_DEBUG, "MSCHAPV2: Auth Response",
auth_response, MSCHAPV2_AUTH_RESPONSE_LEN);
/* Generate master_key here since we have the needed data available. */
if (pwhash) {
if (hash_nt_password_hash(password, password_hash_hash))
return -1;
} else {
if (nt_password_hash(password, password_len, password_hash) ||
hash_nt_password_hash(password_hash, password_hash_hash))
return -1;
}
get_master_key(password_hash_hash, nt_response, master_key);
wpa_hexdump_key(MSG_DEBUG, "MSCHAPV2: Master Key",
master_key, MSCHAPV2_MASTER_KEY_LEN);
return 0;
}
int mschapv2_verify_auth_response(const u8 *auth_response,
const u8 *buf, size_t buf_len)
{
u8 recv_response[MSCHAPV2_AUTH_RESPONSE_LEN];
if (buf_len < 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN ||
buf[0] != 'S' || buf[1] != '=' ||
hexstr2bin((char *) (buf + 2), recv_response,
MSCHAPV2_AUTH_RESPONSE_LEN) ||
os_memcmp(auth_response, recv_response,
MSCHAPV2_AUTH_RESPONSE_LEN) != 0)
return -1;
return 0;
}